Background: Rotary biomechanical root canal preparation is usually associated with dentin micro-cracks.
Aim: to assess and compare the effect of file systems manufactured with different Ni-Ti technologies on root dentin micro-cracking as a measure for integrity.
Materials and methods: seventy single canalled premolar root specimens of equal length were divided into seven equal groups (n=10) according to the canal preparation system used. G1 (Protaper universal), G2 (Protaper next), G3 (Protaper gold), G4 (Vortex Blue), G5 (XP Shaper), G6 (Hand K- files) and G7 left unprepared (control). The specimens were thereafter horizontally sectioned at three levels from root apex and accordingly groups were subdivided into 3 subgroups. Subg1 (3 mm), subg2 (6 mm) and subg3 (9 mm). The root sections were dye stained and examined under stereo light microscope for crack detection. The collected data were statistically analyzed.
Results: Only group 4 & group 5 (single-file rotary groups) were comparable to the control group which showed a lower crack incidence than all other groups (hand files and multi-file rotary groups).
Conclusion: The XP shaper and Vortex blue file systems have a tendency to cause fewer dentinal cracks compared with the Protaper Universal, Protaper Next and Protaper Gold file systems.